Medication delivery pens are hypodermic syringes used for self-injection of precisely measured doses of medication. Pens are widely used, for example, by diabetics to dispense insulin.
A typical prior art medication delivery pen includes a cartridge that contains a volume of liquid medication sufficient for several doses. The dose is delivered into a tissue area, such as the intramuscular tissue layer, the subcutaneous tissue layer, or the intradermal tissue layer.
Following an injection with a drug delivery pen 100, as shown in FIGS. 1 and 2, the pen needle, which includes the hub 20 and needle 11, are unthreaded from the lower housing 17 and disposed in a sharps container. Current sharps containers for residential use have an internal volume of approximately 1.4 quarts (1.32 liters) and can accommodate approximately 300 pen needles. Accordingly, a need exists for reducing the size of the sharps requiring disposal, thereby increasing the capacity of the sharps container. Additionally, by reducing the size of the sharps requiring disposal, the volume of the sharps container may be decreased while increasing its capacity.
Furthermore, when separating the needle from the hub of the pen needle, the drug fluid path should not be disturbed to prevent the generation of potentially biohazardous aerosol particles. Accordingly, a need exists for removing the needle from the hub of a pen needle without disturbing the drug fluid path.